Number Series Aptitude Q & A – Part 5

This is the Part 5 Aptitude Questions and Answers section on “Number series“ with explanation for various interview, competitive examination and entrance test. Solved examples with detailed answer description, explanation are given and it would be easy to understand.

41. Look at this series: 2, 6, 18, 54, … What number should come next?
A. 108
B. 148
C. 162
D. 216Answer:
C. 162Explanation:
This is a simple multiplication series. Each number is 3 times more than the previous number.

44. 1 10 7 20 13 30 19
A. 26 40
B. 29 36
C. 40 25
D. 25 31Answer:
C. 40 25Explanation:
Here, every other number follows a different pattern. In the first series, 6 is added to each number to arrive at the next. In the second series, 10 is added to each number to arrive at the next.

45. 7 9 66 12 14 66 17
A. 19 66
B. 66 19
C. 19 22
D. 20 66Answer:
A. 19 66Explanation:
This is an alternating addition series with repetition, in which a random number, 66, is interpolated as every third number. The regular series adds 2, then 3, then 2, and so on, with 66 repeated after each “add 2” step.

46. 2 44 4 41 6 38 8
A. 10 12
B. 35 32
C. 34 9
D. 35 10Answer:
D. 35 10Explanation:
Here, there are two alternating patterns, one addition and one subtraction. The first starts with 2 and increases by 2; the second starts with 44 and decreases by 3.

47. Look at this series: 15, __, 27, 27, 39, 39, … What number should fill the blank?
A. 51
B. 39
C. 23
D. 15Answer:
D. 15Explanation:
In this simple addition with repetition series, each number in the series repeats itself, and then increases by 12 to arrive at the next number.

48. Look at this series: 72, 76, 73, 77, 74, __, 75, … What number should fill the blank?
A. 70
B. 71
C. 75
D. 78Answer:
D. 78Explanation:
This series alternates the addition of 4 with the subtraction of 3.